hey lele!
congrats on permantly keeping skippy
you will absolutely fall in love with
ACF
i rescue and rehome them quite often as well too, so if you ever want
another, just let me know 
a whisper 20-40 will be fine on a 10 gal. tank for the time being and will be
adequte enough for a 20 gallon long tank housing up to 3 frogs.
advanced power filters are basically the same thing, just diffrent filter
cartridges (and price tags).
those small junior heaters are only for 2-5 gallons i think (maybe they go as
high as 10 gallons) and are only 7 watts. there is a rule of thumb regarding
wattage per gallons of water but icant remember it right off the bat, but
either way, the heater will be too small for a 10 gallon tank. and also, the
frogs really do well in warmer water at all. even if the temp is
fluxuating like that. they do best in cooler water, even if you think its too
cool for them. my house gets very cold and drafty during winter time, and my
frog tanks stays around 63F at the lowest! and my frogs do just fine at this
temp, i just feed them much less then normal since their bodies are in a
winter state. regardless of heater or not, you do not want the temp. to climb
past 73 F, so use a thermometer and watch it closly. oh, also, frogs can
easily burn themselves on the heaters too. so you'll need to get those plastic
heater guards if u decide to use one, which i strongly suggest not doing. they
don't need heated water.
i used river rocks for a few months. and they trap more dirt and debris then
the actual gravel itself and are a pain to clean. i would avoid them unless
your really have the time to clean them. a gravel i have been working with now
is the smallest gravel i have ever seen! it is called "Walnut Shell" and is a
small brown natural stone, smaller then a pea! easy to clean with a syphon,
traps less then larger stones, and is very easily passed incase injested. your
petstore should be able to order it for you, i'm in the process of switching
all my aquatic tanks over to it.
let me know what you decide to do!
btw, how is Luna? i've been ofline for a few days now....
rachel
ps. oh btw, not eating for some time is NORMAL. sometimes my frogs will "fast" for a month or so before deciding to eat! this usually happens when you switch tanks, change decor, move them, breed them, etc. these frogs are totally adapted and hardy, which is why they are so invasive and illegal in 13 states...they can survive for weeks to months without food. so trust me, skippy isnt giong to starve
teaching a frog to eat from the surface takes some time. try turning off the light and filter first and then offer some food. make little taps on the top of the tank and water surface with your fingers to attract his attention as well. this always worked when training my frogs to surface feed. you can also intice him to eat by using a "stinky" food such as beefheart or bloodworms. but use these sparingly as frogs can get dependent on them and refuse better foods (reptomin). also bloodworms can cause acute bloat (article on my site under diseases page). also, make sure he has plenty of hiding spots and that you turn off the light at night for him. they can be skittish and need to feel secure. keep in touch! let me know how it goes.
In Depth Information On Common Aquatic Frogs
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4.3 African Clawed Frog
3.3 Calfornia Newt
0.1 Leucistic Texas Ratsnake
1.1 Veiled Chameleon
0.1 Albino Cranwells Horned Frog
0.1 Paddle Tail Newt
0.1 Green Iguana
0.5.0 Indonesian Floating Frog